GB2293784A - Bending apparatus - Google Patents

Abstract

A bending apparatus has a die (10) and a clamp (46) adapted to clamp an elongate workpiece into engagement with the die (10), the clamp (46) being mounted on a support structure (20) for movement about the die (10), the clamp being arranged to move linearly between a clamping position and a retracted position and a ram (40) being provided to move the clamp (46) out of the plane of linear movement of the clamp (46) relative to the die (10). <IMAGE>

Description

BENDING APPARATUS The present invention relates to bending apparatus and in particular to bending apparatus in which an elongate workpiece is clamped against a die and the clamp is moved around the die to bend the workpiece to the configuration of the die.

With such bending apparatus when the clamp is withdrawn linearly to release the workpiece, the clamp may interfere with the removal of the workpiece from the die or insertion of the next workpiece into the die. In order to improve access to the die, the clamp may be arranged to approach the die on an arcuate path, so that when withdrawn it is located at a level below the die, thus giving unobstructed access to the die.

Arcuate movement of the clamp in this manner does however significantly reduce the operating speed of the apparatus in comparison with linear clamping. Furthermore, access will depend upon the workpiece and the bends to be formed in the workpiece and consequently a linear actuating clamp may be desirable in some circumstances.

According to one aspect of the present invention a bending apparatus comprises a die and a clamp adapted to clamp an elongate workpiece into engagement with the die, the clamp being mounted on a support structure for movement about the die, the clamp being arranged to move linearly between a clamping position and a retracted position and means being provided to move the clamp out of the plane of linear movement of the clamp relative to the die.

With the bending apparatus described above, when additional access is required the clamp may be moved out of the plane of linear movement to permit removal of the workpiece and/or loading of the next workpiece.

However, when access to the die is not a problem, the clamp may be maintained in the plane of linear movement of the clamp relative to the die, removal and/or loading of the workpiece being permitted by linear movement of the clamp to its retracted position, the operating cycle period is thereby significantly reduced thus improving the overall efficiency of the bending apparatus.

An embodiment of the invention is now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a partial side elevation of a bending apparatus formed in accordance with the present invention with a clamping mechanism in a retracted position; Figure 2 is an end elevation of the bending apparatus shown in Figure 1; Figure 3 is a view similar to Figure 1 with the clamping mechanism in an intermediate position; and Figure 4 is a view similar to Figure 1 with the clamping mechanism in a clamping position.

As illustrated in the accompanying drawings a bending apparatus comprises a die 10 defining a groove 11, the cross section of the groove 11 corresponding to the cross-section of an elongate workpiece, for example a tube, to be bent using the apparatus.

A clamping mechanism 1 5 is mounted with respect to the die 10 and is movable relative thereto so that it may be moved around the die 10 drawing the elongate workpiece around the die 10 and bending it to the configuration of the die 10. The die 10 will normally be of circular configuration, the clamping mechanism 15 being pivotally mounted about the axis of the die 10. The die 10 may however be of other curved configuration, suitable guide means being provided to guide movement of As illustrated in Figure 1, the ram 40 and links 31, 32 are arranged such that when the ram 40 is fully retracted, the carriage will be located in a retracted position in which the clamping head 46 is located at a level below the die 10 and is spaced laterally from the die 10.

With the ram 40 in its fully extended position as illustrated in Figure 3, the links 31 and 32 are rotated to lift the carriage 30 so that the clamping head 46 is on a level with the die 10. The arcuate movement of the links 31, 32 will also move the clamp head 46 laterally towards the die 10.

With the ram 50 in its fully retracted position as illustrated in Figures 1 and 3, the links 51 and 52 are inclined to one another and the clamping head 46 is separated linearly from the die 10. When the ram 50 is extended, pivot 56 is moved away from pivot 55 and the clamping head 46 is moved linearly towards the die 10, until when the ram 50 is fully extended, as illustrated in Figure 4, the clamping head 46 will clamp a workplace located between it and the die 10, to the die 10 and the links 51 and 52 are disposed in a straight line. The links 51 and 52 will thus transmit the clamping load directly to the carriage 30. The clamping mechanism 15 may then be rotated around the die 10 by conventional means in order to bend the workpiece to the configuration of the die 10.

With the apparatus described above, the rams 40 and 50 may be used to move the clamping head 46 between the clamping position as illustrated in Figure 4 and the retracted position as illustrated in Figure 1 or ram 40 may be maintained in its extended position and ram 50 may be used to move the clamping head 46 between the clamping position illustrated in Figure 4 and the intermediate position illustrated in Figure 3, as required by the workpiece and the bends to be formed therein.

The rams 40 and 50 may be controlled by programmable means which is capable of deciding whether full or partial retraction of the clamping head the clamping mechanism 15 so that movement thereof will cause the workpiece to be drawn around the die 10.

The clamping mechanism 15 comprises a support structure 20 which is mounted on an axle 21 which extends coaxially of the die 10, for rotation about the axle 21. The support structure 20 has a pair of side plates 22, 23 which are parallel to the axis of rotation of the support structure 20 on the axle 21, the plates 22, 23 being mounted in parallel spaced apart relationship to one another.

A carriage 30 is located between the side plates 22 and 23, the carriage 30 being connected to the plates 22 and 23 by two pairs of links 31, 32 one pair on either side of the carriage 30, each pair of links 31, 32 defining a parallelogram linkage. Links 31 on each side of the carriage 30 are pivotally attached to the carriage 30 at one end 35 and pivotally attached to the side plates 22 and 23 at an intermediate position 36. The end 37 of the links 31 remote from the carriage 30 is connected to a double acting ram 40, the other end of the ram 40 being attached to the plates 22 and 23 by a pivot 41 extending therebetween.

The upper edge of the carriage 30 defines a slide formation 45 upon which is mounted a clamping head 46, so that the clamping head 46 is slidable linearly of the carriage 30. A second double acting ram 50 is pivotally attached at one end 51 to the carriage 30, the other end of the ram 50 being connected; by a first link 52 to the carriage 30; and by a second link 53 to a lug 54 on the clamping head 46. The link 51 is connected to the carriage 30 by pivot 55 and link 53 is connected to lug 54 by pivot 56, the line connecting the axes of rotation of the pivots 55 and 56 being parallel to the sliding surface of the slide formation 45.

The clamping head 46 has a clamping face 47 which has a groove 48 corresponding to the groove 11 in die 10.

40 is required, from the characteristics of the workpiece and the bends required which are programmed into the control system. Proximity sensing means may also be incorporated into the apparatus to assist in programming of the control system and to detect malfunction of the apparatus.

Various modifications may be made without departing from the invention.

For example, vertically disposed multiple clamping heads may be slideably mounted on the carriage for engagement of vertically disposed multiple dies which may, for example, be of different radii of curvature and/or have different die cavities to accommodate workpieces of different crosssections.

Claims (8)

1. A bending apparatus comprising a die and a clamp adapted to clamp an elongate workpiece into engagement with the die, the clamp being mounted on a support structure for movement about the die, the clamp being arranged to move linearly between a clamping position and a retracted position and means being provided to move the clamp out of the plane of linear movement of the clamp relative to the die.

2. A bending apparatus according to Claim 1 in which the clamp is slidably mounted with respect to the support structure for linear movement relative thereto.

3. A bending apparatus according to Claim 2 in which the clamp is connected to the support structure by means of a pair of links, the links being pivotally interconnected at one end, the other end of one link being pivotally connected to the clamp and the other end of the other link being pivotally attached to the support structure, means being provided to move the pivotally interconnected ends of the links between one position in which the links are inclined with respect to one another and the clamp is in its retracted position and a second position in which the links are disposed linearly of one another, and the clamp is in its clamping position.

4. A bending apparatus according to Claim 3 in which a double acting ram moves the pivotal interconnection of the links, the ram being arranged such that when fully retracted, the clamp will be in its retracted position and when fully extended the ramp will be in its clamping position.

5. A bending apparatus according to any one of the preceding claims in which the support structure includes a carriage, the clamp being slideably located on the carriage, the carriage being mounted for movement between a first position in which the clamp is disposed linearly of the die and a second position in which the clamp is moved out of the plane of linear movement of the clamp with respect to the die.

6. A bending apparatus according to Claim 5 in which the carriage is mounted on a parallelogram linkage so that it will move arcuately between the position in which the clamp is disposed linearly of the die and the position in which the clamp is out of plane of linear movement of the clamp relative to the die.

7. A bending apparatus according to any one of the preceding claims in which a double acting ram acts to move the clamp between a position in which the clamp is disposed linearly of the die and the position in which the clamp is out of the plane of linear movement of the clamp relative to the die.

8. A bending apparatus substantially as described herein, with reference to and as shown in the accompanying drawings.